reminds me of how way back in middle school i made a mmo-styled chat world in nothing but a shared google sheet. it lasted 2 weeks before the teachers had to ruin the fun for everyone (their excuse was that people typed slurs in it, but that's bs because I would erase their edits and permanently ban them within minutes).
i would also share obfuscated links to games and such on a hidden page, good times.
Veloren, it's basically Hytale before Hytale
EDIT: It's also open source